Human beings are rational animals. We're not the only rational animals, contra Aristotle; the great apes and some birds, for example, behave rationally in many situations and sometimes show remarkable flashes of insight. Even if we're not uniquely rational, though, human beings are more rational, more often.

But it's not built into our nature. It doesn't come for free. Being rational is hard work.

I'll illustrate. Now that Rick Perry has been taking his turn (off and on) as frontrunner among Republican candidates for President, some of his earlier statements have gained some publicity. Last year Perry was interviewed on television by Evan Smith, editor-in-chief of the Texas Tribune.

Smith asked, Why does Texas continue with abstinence education programs when they don't seem to be working? In fact I think we have the third highest teen pregnancy rate in the country.

Perry answered, "Abstinence works."

...But it doesn't seem to be working.

"It works... I'm just going to tell you, from my own personal life. Abstinence works."

Perry visibly struggled for three solid minutes, offering nothing more than assertions of his belief. He was in a spot. You might expect a social conservative to say, "Sex education for teenagers should be limited to abstinence education; anything else would be immoral." But Perry also expresses small-government views, and you'd expect a small-government conservative to say, "The government shouldn't be in the business of sex education." He couldn't square the circle.

This is what I mean by rationality being hard work. A rational person takes evidence into account when forming beliefs. It takes work to find and consider that evidence. A rational person even looks for evidence weighing against a belief, and revises if needed. That also means work. And managing beliefs so that they don't contradict each other--that's the hardest of all.

Beliefs without evidence, even beliefs despite evidence, aren't unusual in the modern world. (I sometimes wonder whether we're less superstitious than our medieval ancestors.) Here are a few common beliefs, according to recent polls:

Most Americans believe that angels and demons are active in the world today. (This from a 2008 Washington Post poll.)

Many Americans believe that prayer can avert or ameliorate natural disasters.

Many Americans believe that Jesus Christ will return to Earth within their lifetime. (This from a 2010 Pew survey.)

I use these examples because they have a few things in common. They're not based on any reasonable evidence. The world is not driven by supernatural inflences--at least, angels and demons have never been seen, and most happenings can be explained by natural causes. Prayer has been tested in experiments. It gives some people the personal fortitude to deal with natural disasters, but it doesn't directly affect the earth or wind or rain. It doesn't work that way. And the Bible has never been a good predictor of current events, much less the end of the world. These beliefs also have political implications. Should a politician "demonize" some group of people? Given a belief in literal demons, why not? How should a politician deal with, say, a severe drought? Given a belief that prayer works, perhaps an official proclamation for a day of prayer. How should long-term political or economic problems in the world be dealt with? Here's an analogy: You're alone in the world, with no family or dependents, and you believe you have a terminal disease. If you're going to die in a week, do you bother to pay your bills?

Many beliefs without evidence are harmless. Some are not. They take our attention away from real problems and real potential solutions.

One of the hardest things about being rational is revising one's beliefs to reflect new evidence. I've acquired many of my beliefs, for example, from authority figures in my life, from people I've trusted. Like most people, I gravitate toward others who share my beliefs. And like every human being, I have built-in biases in the way I interpret and think about the world around me. Giving up a specific belief may involve more than rearranging the thoughts in my head. It could mean changing my mind about the views of someone I respect. It could push me away from a circle of friends. It might even overturn some of my thoughts about who I am as a person.

Does this seem worthwhile? Actually, it does, if the stakes are high. After all, I like to think of myself as a rational beast.

 Cross-posted at Does This Makes Sense?